Note 218 — Chapter XX
Reading edition
The origin of the vaso-peritoneal vesicle is not quite the same in all the species. In Holothuria tubulosa it is separated from the cæcal end of the archenteron; the remainder of which then grows towards the oral invagination. In Cucumaria the archenteron forks (fig. 249); and one fork forms the vaso-peritoneal vesicle, and the other the major part of the mesenteron.